Thief line for butane tanks



Feb. 1, 1949. HUGHES THIEF LINE FOR BUTANE TANKS Filed June 7, 194a 1/171! 1/ I? Ill/1111111111!!! ATTORNEY Patented Feb. 1, 1949 UNITED 1 r 2,460,454- v THIEF'LIN'E Fon BUTANE TANKS Landrum L. Hughes, Erick, Okla. Application June '7, 194.6, Serial No. 675,286

3 Claims.

My invention relates to underground storage tanks for liquefied butane gas, and more particularly to a thief line whereby liquid butane may be drawn from the tank.

Many farms and rural households depend for fuel upon butane gas, and in most instances, the gas is stored in tanks buried beneath the earths surface. The storage tanks are buried, not only to prevent freezing, but also as a safety precaution against fire hazard.

It is a commonly known fact that automotive vehicles can be more economically operated upon butane than upon gasoline, but due to inaccessibility of the buried storage tanks, few persons use the butane to operate their farm trucks, tractors, etc., even though they have it constantly on hand.

The principal object of the present invention is to provide a thief line, for buried butane storage tanks, which will deliver the butane from the tank to a point of accessibility above ground.

Another object is to provide a thief line for this purpose which, from the fire hazard standpoint, is safe to operate.

A further object is to provide a thief line of this class which is simple to install, simple to operate, and comparatively cheap to manufacture.

Other objects will be apparent from the following description when taken in conjunction with the accompanying single sheet of drawings,

wherein: I I

The figure is an elevational sectional view of a typical underground butane storage tank, the thief line of the present invention being shown operatively installed therein.

In the drawings:

The reference numeral I indicates, as a whole, a usual tank for storing liquefied butane gas. The tank I is usually entirely buried beneath the earth's surface, and has an upwardly projecting metal dome 2 mounted thereon and protruding above the ground. The dome '2 houses usual mechanism for drawing ofi 'gasified butane which accumulates in the upper portion of the tank. The mechanism usually includes: a vertical gas collecting riser 3 having its lower open end located in the upper portion of the tank; a control valve 4; a pressure regulator 5; and a service line 6 leading to a point of gas consumption. The dome 2 has a removable cap I. The elements thus far described are usual to present day butane storage and service methods, and are not pertinent to the present invention, except that 2 the tank I and dome 2 act to house the present invention.

The device of the present invention includes:

A vertically disposed pipe or line I 0 having its lower open end II disposed adjacent the bottom of the tank I where it will be located below the normal liquid level in the tank. The thief pipe I0 passes upwardly through the top of the tank into the dome 2, and is hermetically sealed with the tank top. The body of liquid butane in the tank I is indicated by the reference numeral I2.

Within the tank I, the pipe 10 is equipped with a suitable automatic excess-flow check valve I3 whereby fluid may pass therethrough at a moderate speed, but not at a high velocity. A pipe I4, above the valve I3, connects the valve to a suitable hand operated control valve I5, and the upper end of the valve I5 is provided with a pipe nipple I6 having threads I! on its upper end. The threads I1 are for the purpose of re,- ceiving a flexible hose, not shown.

When it is desired to draw liquid butane from the tank I, it is only necessary to lift the dome lid 1, connect the delivery hose, and open the valve I5. Gas pressure in the tank above the liquid I2, acts to force the liquid upwardly through the pipe I0, valve I 3, pipe I 4, valve I5, and nipple IE to the hose.

It is obvious that the present device will make butane easily accessible for use in automotive vehicles on the farm and rural communities.

Obviously the device is subject to some modification without defeating its practicability, and I therefore do not wish to be confined to the preferred embodiment shown in the drawings and described hereinabove, further than I am limited by the scope of the appended claims.

Iclaim:

1. The combination with a sub-surface storage tank for liquefied butane having a dome thereon for which the tank top forms a floor, of a thief line including: an outlet pipe passing from within the dome downwardly through the top of the tank and hermetically sealed thereto, said pipe having an open lower end located adjacent the bottom thereof; a cut-off valve on the pipe outside of the tank; and an excess-flow-check valve intermediate the ends of the pipe and located within the tank adjacent the top thereof.

2. The combination with a sub-surface storage tank for liquefied butane having a dome thereon for which the tank top forms a floor, of a thief line including: an outlet pipe extending from the dome downwardly through the tank top to a point adjacent the bottom thereof; means for hermetically sealing the tank top to the exterior of the pipe; and an eXcess-flow-check intermediate the ends of the pipe and located within the tank adjacent the top thereof.

3. The combination with a sub-surface storage tank for liquefied butane having a dome thereon for which the tank top forms a floor, of

a thief line including: an outlet pipe extending" The following references are of file of this patent:

4 REFERENCES CITED record in the UNITED STATES PATENTS Number Name 7 Date Little July 18, 1939 White Oct. 17, 1939 Hooper et al.. -Jan. 9, 1940 Hooper -Mar. 26, 1940 White Oct. 28, 1941 Sundstrom Dec. 1, 1942 Norway Oct. 31, 1944 

